Up to now, one of high-quality SiC single crystal wafer is disclosed in Patent Literature 1. In the SiC single crystal wafer disclosed in Patent Literature 1, a density of dislocation that adversely affects device characteristics is set to a specified value or lower, specifically, in wafer having a diameter of 3 inches, the dislocation density is set to 2500 cm−2 or lower so as to be intended for device production. In the present specification, the dislocation means linear crystal defects, and a target dislocation is a spiral dislocation having a direction parallel to a c-axis.
However, the present inventors have earnestly conducted studies on the basis of experiments, as a result of which it is found that even if the density of the spiral dislocation is merely set to the specified value or lower, the SiC single crystal suitable for the device production which can suppress a leakage current, as shown in Patent Literature 1, is not obtained.